1. Technical Field
The present invention generally relates to application management in a computing environment. More particularly, the present invention relates to controlling a number of instances of an application running in a computing environment.
2. Background Information
Computing environments typically have some mechanism for managing the resources of that environment. One example of a computing environment that manages resources is a clustered environment. As is known, a cluster is a high-bandwidth connected set of computers which serve to run applications that are to be highly available. Clusters are used for deploying various applications, and examples include database servers and web servers. These applications make use of cluster resources, such as disks, network adapters, IP addresses, operating system services and application software. Clustered environments include cluster managers, which are responsible for managing the resources of the cluster.
In managing the resources, the cluster manager recognizes various constraints associated with the individual resources. These constraints relate resources to each other and specify the parameters of the individual resource with which it is associated.
In the past, such computing environments have not controlled the number of instances of a given application that is running. The ability to control the number of instances allows for responding to changes in loads on individual applications, thereby making more efficient use of resources.
Thus, a need exists for a way to control the number of instances of an application running in a computing environment.
Briefly, the present invention satisfies the need for a way to control the number of instances of an application running in a computing environment by specifying limits on the number of instances, monitoring the current number of instances running, and altering that number based on the limits.
In accordance with the above, it is an object of the present invention to provide a way to control a number of instances of an application running in a computing environment.
The present invention provides, in a first aspect, a method of controlling a number of instances of an application running in a computing environment. The method comprises monitoring a current load on an application running in the computing environment, and altering a current number of instances of the application running in the computing environment based on results of the monitoring. The monitoring may comprise monitoring the current number of instances of the application. At least one of a maximum, minimum, and initial number on startup, of instances of the application may be specified.
The present invention provides, in a second aspect, a system for performing the method of the first aspect.
The present invention provides, in a third aspect, an article of manufacture, comprising at least one computer usable medium having computer readable program code means for causing a computer to perform the method of the first aspect.
These, and other objects, features and advantages of this invention will become apparent from the following detailed description of the various aspects of the invention taken in conjunction with the accompanying drawings.